Shivaji University

About: Shivaji University is a education organization based out in Kolhāpur, Maharashtra, India. It is known for research contribution in the topics: Thin film & Scanning electron microscope. The organization has 3078 authors who have published 5295 publications receiving 115397 citations.

Direct synthesis of well-ordered mesoporous Al-SBA-15 and its correlation with the catalytic activity

Abstract: The synthesis of Al-SBA-15 under milder acidic conditions were made through an adjusting the molar H2O/HCl ratio which indicate the formation of Si–O–Al linkages that lead to isomorphous substitution of Si4+ by some Al3+ ions. By adjusting the H2O/HCl molar ratio, Al gets incorporated into the lattice of SBA-15, which is evidenced by XRD, N2 adsorption, TEM, 29Si and 27Al MAS NMR spectroscopic data. Aluminium incorporated SBA-15 samples retained both structural and textural properties of SBA-15. The 27Al MAS NMR confirms that a large proportion of the Al is inserted into tetrahedral positions within the framework. The Al3+ ions could assume a tetrahedral coordination and be part of the hexagonal structure of silica in Al-SBA-15. In the present study, we have examined the effectiveness of Al-SBA-15, as an acid catalyst for the esterification of acetic acid and in benzylation of anisole. The high activity of Al-20 sample in esterification reaction has been attributed to isolated, generally tetrahedrally coordinated, framework Al species. While in benzylation of anisole, the best result was achieved with Al-5 catalyst. The selectivity for benzylanisole increases and that for dibenzylether decreases with increase in the Si/Al ratio of Al-SBA-15.

Synthesis and characterization of pure anatase TiO2 nanoparticles

Abstract: Pure anatase TiO2 nanoparticles were synthesized by microwave assisted sol–gel method and further characterized by powder X-ray diffraction (XRD), energy dispersive x-ray analysis (EDAX), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV–Visible spectrophotometer, SEM images showed that TiO2 nanoparticles were porous structure. The XRD patterns indicated that TiO2 after annealed at 300 °C for 3 h was mainly pure anatase phase. The crystallite size was in the range of 20–25 nm, which is consistent with the results obtained from TEM images. Microwave heating offers several potential advantages over conventional heating for inducing or enhancing chemical reactions.

Fabrication and performance of polypyrrole (Ppy)/TiO2 heterojunction for room temperature operated LPG sensor

Abstract: In this paper, we report on the fabrication and performance of room temperature operated liquefied petroleum gas (LPG) sensor based on polypyrrole/TiO 2 (Ppy/TiO 2 ) heterojunction. Ppy/TiO 2 heterojunction was prepared by sequencial depositing TiO 2 film by chemical bath deposition and Ppy film by electrodeposition method. Ppy and TiO 2 films were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), FTIR and thermo-emf techniques. The XRD study revealed amorphous and nanocrystalline natures for Ppy and TiO 2 films, respectively. The SEMs of Ppy and TiO 2 films showed cauliflower-like and densely compact morphologies respectively. Maximum gas response of 55% was observed for Ppy/TiO 2 heterojunction at 1040 ppm of LPG. Relative humidity affected the gas sensing performance of heterojunction. Good stability, fast response and recovery times indicate that Ppy/TiO 2 heterojunction is a one of the candidate for room temperature LPG detection.